CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Capital in Excess Of Par Value [Member]	Reinvested Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interest [Member]	Total
Balance at Dec. 31, 2017	$ 10,162	$ 55,884	$ 150,350	$ (17,859)	$ 7,122
Net earnings (loss)	0	0	20,484	0	(525)	$ 19,959
Foreign currency translation adjustments	0	0	0	(1,604)	(472)	(2,076)
Pension liability adjustment, net of tax	0	0	0	1,363	0	1,363
Cash dividends declared	0	0	(9,297)	0	0
Cash dividends paid to noncontrolling interest of subsidiary	0	0	0	0	(88)
Reclassification of stranded tax effects from the adoption of ASU 2018-02 at Dec. 31, 2017	0	0	2,361	(2,361)	0
Acquisition of noncontrolling interest	0	3,408	0	(1,111)	(6,037)
Common stock issued under equity incentive plans, net of shares withheld for employee taxes and strike price	225	3,479	0	0	0
Issuance of restricted stock	25	(25)	0	0	0
Restricted stock forfeited	(4)	4	0	0	0
Share-based compensation expense	0	1,513	0	0	0
Shares purchased and retired	(351)	0	(11,063)	0	0
Balance at Dec. 31, 2018	10,057	64,263	152,835	(21,572)	0	205,583
Net earnings (loss)	0	0	20,882	0	0	20,882
Foreign currency translation adjustments	0	0	0	(132)	0	(132)
Pension liability adjustment, net of tax	0	0	0	(2,832)	0	(2,832)
Cash dividends declared	0	0	(9,466)	0	0
Common stock issued under equity incentive plans, net of shares withheld for employee taxes and strike price	8	148	0	0	0
Issuance of restricted stock	31	(31)	0	0	0
Share-based compensation expense	0	1,452	0	0	0
Shares purchased and retired	(223)	0	(5,426)	0	0
Balance at Dec. 31, 2019	$ 9,873	$ 65,832	$ 158,825	$ (24,536)	$ 0	$ 209,994